Display screen or portion thereof with an animated graphical user interface



FIG. 1 is a front view of a first image of a display screen or portionthereof with an animated graphical user interface showing the newdesign; and,

FIG. 2 is a front view of a second image thereof.

The outermost broken line rectangle illustrates a display screen orportion thereof and forms no part of the claimed design. The remainingbroken lines illustrate portions of the graphical user interface thatform no part of the claimed design.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-2 . The process or period in whichone image transitions to another forms no part of the claimed design.

CLAIM I claim the ornamental design for a display screen or portionthereof with an animated graphical user interface, as shown anddescribed.